The present disclosure relates to a plasma electrode device.
Recently, constructed buildings receive minimum external air and are sealed off from the outside for energy saving, and thus air pollution therein becomes more serious. Accordingly, mandatory regulations for indoor pollutants are being increasingly reinforced.
Meanwhile, during operations of home appliances installed at home or offices, indoor pollutants may be stuck to or discharged from the home appliances. The indoor pollutants may cause unpleasant smells and have a negative influence on user's health. For example, in the case of home appliances, such as air conditioners, dehumidifiers, air cleaners, refrigerators, and washing machines, which use air containing moisture or water, contamination due to dust or microorganisms may occur inside or outside the home appliances.
More specifically, the indoor pollutants may be classified into (1) particulate pollutants such as fine dust and asbestos, (2) gaseous pollutants such as carbon dioxide, formaldehyde, and volatile organic compounds (VOC), and (3) biological pollutants such as virus, fungi, and bacteria.
Surface discharge plasma chemical processing may be used to remove such indoor pollutants. In general, in the surface discharge plasma chemical processing, high intensity plasma is generated on a device surface by high frequency discharge using ceramics to generate a large amount of OH radicals, and then the pollutants are removed by the OH radicals and ozone in the plasma.
One example of the following technique (hereinafter, referred to as “the related art”) is disclosed in Korean Patent No. 10-0657476 (issued on Dec. 7, 2006 and entitled “Surface discharge type air cleaning device”) filed by the present applicant.
The air cleaning device according to the related art includes a discharge electrode provided on a top surface of two sheet of insulating dielectrics that are attached to each other, a ground electrode interposed between the two sheet of insulating dielectrics, and a coating layer sealing the discharge electrode to prevent the discharge electrode from being directly exposed to the air. Here, each of the insulating dielectrics may be coated with an insulating material. For example, the insulating material includes ceramics.
When the insulating dielectric is coated with the insulating material or includes the coating layer, the surface of the electrode has to be uniformly coated to generate uniform discharge. However, in the case of the plasma electrode device according to the related art, it is very difficult to form the coating having a uniform thickness, and uneven patterns beyond an allowable range are formed on the surface in the coating process.
In addition, the plasma electrode device according to the related art may generate an insufficient amount of ions, and thus it may be difficult to remove effectively pollutants. Further, a large amount of ozone that is harmful to humans may be generated during the plasma discharge.